


Waterloo

by Nabatean_Nan



Series: Setleth Modern AU [2]
Category: Fire Emblem: Fuukasetsugetsu | Fire Emblem: Three Houses
Genre: Aftercare, Breast Fucking, Dorks in Love, F/M, Nipple Piercings, Post-Coital Cuddling
Language: English
Status: Completed
Published: 2019-09-12
Updated: 2019-09-12
Packaged: 2020-10-14 21:56:36
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 3,225
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/20607971
Author URL: https://archiveofourown.org/users/Nabatean_Nan/pseuds/Nabatean_Nan
Summary: Seteth and Byleth play while Flayn is away.





	Waterloo

**Author's Note:**

> listen,,,,, this is literally my first smutfic...... i've never ever published smut before so blease..... go easy on me.....

“Your piercing,” Seteth says one day, during a shared lunch, as if he’s made a grand discovery. “The one in your ear. When did you get that?”

Byleth smirks and takes a sip of her mocha. “I have a lot of piercings in my ear, Seteth.”

He smirks right back at her. “The one _ in _ your ear. I’m not certain what it’s called. Obviously you have your lobes and your cartilage pierced. But on your left ear, I don’t know what that one is called. Forgive me for not being _ hip _ and _ youthful _.”

Byleth reaches up and fiddles with the ring, now that they’re talking about it. It’s hidden away nearly inside her ear, where most people never even notice it. “It’s called a daith,” she says. She figures teasing Seteth isn’t worth it. Really, he’s already teased himself. He was being playful. It was very cute. “I got it for my birthday last year.”

“It’s much... plainer than your other jewelry.”

“It’s not for decoration. It’s supposed to help with migraines.” 

He cocks his head to the side, resting his cheek on his hand. Both of their lunches have been forgotten at this point, not that there was much left to either of them. “Migraines?”

She nods. “It’s some acupuncture thing. I’ve had migraines since high school. Nothing ever helped, or if it did it only helped a couple of times before it seemed like my body just... got used to it and it didn’t work anymore. My dad read about this piercing and thought he’d offer it as a present.” She shrugs. “I mean, it’s helped so far. I’m coming up on a year.”

He picks up a leftover french fry and twirls it around on his plate. Byleth pictures Flayn a few days ago, doing the exact same thing, and Seteth telling her not to play with her food. “No migraines for a year?”

“Not one hundred percent of the time, but they’ve been significantly better. I don’t throw up all the time.”

He grimaces, and Byleth can’t help but think he kind of looks cute with his face all scrunched up like that. “You’re rather fond of less typical piercings, I take it? For your father to suggest that as a birthday present, I mean. If Flayn suffered migraines, I wouldn’t think of a piercing to be an appropriate response.”

She shrugs. “I used to have a lot of facial piercings, but I got tired of them. He used to tease me about them. Told me I only got them to be rebellious.” She shrugs, again, and smiles her little smile. “I was really cute with my eyebrow piercings, but it was such a hassle.” She laughs. “I still have a few of my more... exotic piercings.”

Seteth’s gaze flickers to her but quickly flickers away. He blushes, betraying his interest, and she can’t help but smirk again. “Exotic?”

Byleth reaches out and pats one of Seteth’s hands. “Buy me a few drinks first, Seteth.”

* * *

He forgets about her teasing, for a while. That conversation was during an earlier stage of their relationship. There was definitely some physical attraction between them, but other than a few tentative squeezes, not much had been acted on. Not enough for Seteth to _ see _ Byleth’s exotic piercings. 

At least, not until Flayn’s grandparents offer to watch her for a weekend.

They’re Morrigan’s parents, and they reach out to Seteth on a Wednesday. It’s short notice, but they want to take her to a local lake for the weekend for some fishing and swimming. They have a friend who has a cabin there, who's letting them stay for a few nights. Seteth is invited as well, but he surprises even Byleth when he declines. 

“I think Flayn will enjoy the alone time with her grandparents,” he says. “Though I... have asked them to call me every night, before she goes to bed.”

Of course he has. Byleth doesn’t blame him, really. As far as she is aware, this is Flayn’s first weekend away from home without Seteth. Making a few phone calls before bed isn’t so bad. Some would call Seteth overprotective, a helicopter parent, but Byleth knows he’s just afraid of losing her. He’s allowed to be, she thinks. 

Byleth is there when they send Flayn off. She and Seteth are hoping to make a date night of it, once Flayn is off for the weekend. Byleth isn’t certain how successful that will be, but it’s worth a shot. 

At the current moment, Seteth is busy double-checking to make sure Flayn has everything, holding her in his arms until the very last moment. Once Seteth is appeased, he starts to get ready to set Flayn in her car seat, but she shrieks, “Wait!”

Everyone stops. It’s like the world has stopped. Byleth is frightened for a moment that Flayn’s grandfather has had a heart attack. 

Flayn hops out of the car and runs over to Byleth, giving her a big hug by reaching up to squeeze around her waist. “Goodbye, By By.”

Byleth smiles and kisses the top of her head. “Goodbye, Flayn. Have fun on your trip. Catch a big fish for me.”

That gets her excited. “I will!” She runs back over to the car and climbs her way back in, even buckling herself. “Okay. Bye, Daddy. I’ll catch a big fish for you, too!”

Byleth can’t see the smile on his face as he leans in to give her a goodbye kiss, but she knows it’s there. They wave goodbye together. 

* * *

After Flayn’s goodnight call is finished, Seteth and Byleth bicker playfully on what they intend to watch. Byleth argues that it doesn’t matter since Seteth is supposed to be showing her how to cook anyway. Seteth argues that of course it matters and spouts some rhetoric about the mood. Neither of them really care, and they’re fully aware of it, but eventually, they settle on _ Contact _. It’s just background noise as Seteth guides Byleth through searing a perfect tilapia, which in itself is just an excuse to be close to her. To press against her back, a hand on her hip, another on her shoulder. He isn’t discreet when he places a kiss on her head, or one on her shoulder, but she doesn’t call him out on it.

She burns their asparagus because she’s busy kissing him, her hips pressed against his counter, but it’s alright. Their tilapia is just fine, and Seteth even brings out a wine he bought just for this dinner. Together they drink probably much too much of it. 

By the time Byleth notices the movie is over, their dinner is long finished and her shirt is on the ottoman and Seteth is sucking a hickey into her neck. She’s wearing a lace bralette, something that’s made to look cute rather than to actually offer any support. She had seen him melt when he saw it, his pupils blown wide and his hands subconsciously cupped the air around them as if it was her breasts. 

So, when his hands start to creep up under the band on the bralette, Byleth tugs on his hair. 

He groans, likely thinking she’s edging him on. Perhaps she is. She tugs hard enough to guide his face up, and he looks remarkably divine. 

She leans down to give him a short kiss. “Don’t panic,” she mumbles. And it’s certainly the wine in the first place, the reason that she’s warning him. Normally she lets anyone who gets this far just see it and take it in. Not that many people have gotten this far. “My nipples are pierced.”

His eyes shoot open as if she’s told him the secret of creation. All she can offer is a sly smile as he slides his hands under the cloth of the bralette and pulls it up. 

She’s never been one for fancy piercings. In her ears, sure. Cute studs, cute dangles, large hoops, sure. But elsewhere? Basic barbells only. That’s what she has on her nipples. The most basic surgical steel barbells that money can buy. 

Seteth looks at them as if they’re diamonds. His mouth opens in a cute little _ o _ and his eyes are half-lidded in a tipsy stupor. He’s adorable. Byleth’s heart beats a mile a minute as he reaches a hand out and gently plays with her right nipple. Just rolls it around his finger, tugs on it, uses the jewelry to work her around. 

She bites her lip and tugs gently on his hair again. It’s not enough, and surely he knows that. His eyes flick up to her, something in her core burns hot and bright at the look in his eyes. Together, they shift until she’s lying on the couch and he’s straddling her waist. His weight on top of her is absolutely delicious, but he’s far too clothed. She tosses the forgotten bralette aside and runs her hands up his thighs. His entire _ body _ shivers at her touch. 

“Goddess, you mustn’t tempt me so,” he breathes. He palms both of her breasts, giving them a gentle squeeze before playing with the jewelry on her nipples. “Byleth, I have a selfish request.”

She wriggles under him, panting and moaning when he uses the balls of the barbells to tug on her nipples. Her breasts have always been terribly sensitive, but never so much as they have been in just this moment. “What is it?”

“I... I don’t know what has come over me. You’ve bewitched me.”

She grins. “My breasts have bewitched you.”

He gives her nipples a sharp tug, and she groans from the pleasurable punishment. “Yes,” he says. She’s certain she feels his hips twitch. 

He keeps playing with her nipples, distracted until Byleth reaches up and grasps his wrists. “Seteth?”

His cheeks turn red. “There is... no romantic way for me to ask this of you.”

“Then just be dirty. It doesn’t have to be romantic.”

Seteth nods and closes his eyes. “P-Please allow me to fuck your breasts.”

Oh, he’s so adorable. He wants this to be a romantic first time together, he’s spoken at length about how he wants to sweep her off her feet, but he’s so clearly mesmerized by her tits that all his plans have fallen to the wayside. He’s positively flustered, and the fact that a couple of double Ds and two piercings did that to steadfast Seteth makes something in Byleth’s core ache. 

“Please,” she says. “Please, fuck my tits.”

His face flares even brighter and he leans down to give her a quick peck. “Wait here,” he mumbles against her lips. After that he just... leaves. Goes to his room, she thinks. She takes the opportunity to shimmy her shorts off. She doesn’t know how far they get tonight, but she wants easy access to play with herself either way. 

When he returns, he has a bottle of... moisturizer?

Byleth hums. “What’s a guy like you doing with a bottle of lotion that big beside his bed?”

“_ Hush _,” Seteth says. He places a teasing hand over her mouth. “Or shall I have to gag you?” Her breath hitches at the thought, and he raises an eyebrow. “...Perhaps we will set that idea aside for another night.”

He releases her mouth, and Byleth can’t help the small smile that graces her lips. “You could hardly bear to ask to fuck my tits, Seteth. What makes you think you can bear to gag me?”

He pauses in his efforts to straddle her once more, and she realizes it’s because he’s now busy pouting. What a terrible, adorable man Byleth has found for herself. 

She grabs his wrists and pulls his hands back to her breasts. “I was only teasing.”

“You’ve wounded me,” he mutters. 

She guides his hands around her chest, giving herself teasing touches until he finally finds it within himself to grasp her breasts once more. She gasps when he leans down to take her left nipple into his mouth, using her jewelry as a means to swirl it around with his tongue. Byleth sighs happily, raking her fingers across Seteth’s scalp. 

He releases her nipple with a _ pop _ and leans over to get a pump of the lotion. He rubs it in his hands, and then starts to slather it all over her breasts. Or, rather, he massages it into them. He’s very methodical, running over her tits with gentle pressure, pressing circles from her collarbone down to her abdomen. Byleth closes her eyes and lets her head fall back. She doesn’t think anyone she’s ever slept with before has paid this much attention to her. His fingers feel like magic against her skin. Pushing and pulling, reaching up to tweak her nipples when she least expected it. Pressing soft circles against her, pulling groans and whines from her. 

She doesn’t realize how wet she is until he kisses her. Just a soft peck on her lips, but it makes her cunt ache. She rubs her thighs together as he gets up and removes his jeans and briefs. She can tell that his cheeks are blazing red, and hers are too, really. But there he is, standing at full attention. 

Byleth hasn’t seen many cocks, in her time. Pretty much all of her sexual partners have been women. Technically she sort of gave a blowjob once, but it was a strap on so it doesn’t really count. She gave a handjob to a kid when she was in high school, but he creamed his pants in like two minutes so that was disappointing. The only cocks she’s seen have been fake ones and the ones in porn. 

Seteth’s isn’t like either of them. He’s fairly clean shaven, for one, and uncut. Of course, he’s from Adrestia. The practice isn’t common, there. As he comes to straddle her again, this time her chest, she sees just how _ girthy _ he is, rather than long.  
  
“Are you alright?” He asks softly. He knows this is her first time with an actual, real dick. “Do you need a moment?”

Byleth shakes her head. She decides that rather than stare at his dick the whole time, she wants to stare at him. So she looks up and sees the most tender look in those sweet green eyes she thinks she’s ever seen. 

“I’m okay,” she says. She brings her hands up to squish her breasts together, trapping his cock between them. “Like this?”

Seteth lets out a breathy sigh and begins to gently rock his hips. “Just like that.”

It feels strange, to have him between her breasts. In her mind, when he brought it up, it didn’t seem like anything particularly special. It turned her on, aroused her, whatever. But she didn’t think it would be something that would make her _ cum. _And yet here she is, rubbing her thighs together, trying to get any friction possible because the way his cock slides past her tits makes her feel unbelievably good. 

Byleth certainly isn’t the only one feeling it. Seteth’s eyes are glued shut, his eyebrows pressed together and his mouth is open in that cute little _ o. _ His hand has a vice grip on the top of the couch and Byleth wonders why they didn’t just move to the bed when he went to grab the lotion. 

Then, he picks up the pace. He thrusts a little harder, a little faster, and Byleth sees stars. His cock slips out from her cleavage, and together they put it right back where it belongs and Seteth starts right back up with his pace. The sound of their skin slapping together goes right to her cunt and she prays to the goddess she gets a free hand soon--

“Seteth,” she whines. “Seteth!”

He bites his lip, but she hears a soft, “Yes?”

“Please, please touch me.” She thinks she may be crying, actually crying. “I can’t reach, please.”

He staggers a bit in his pace, but only because he’s reaching back. With his hand that isn’t gripping the couch, he reaches back to touch her through her panties. Just that slight bit of pressure, the little touch, makes Byleth break out a sob. 

She rewards him by craning her neck up and placing a kiss on his cockhead. A small lick, too. There’s a little precum there, and it tastes awful, but the sound he makes is so wonderful that she does it again. Every time he presses against her clit, every time he thrusts forward again, she rewards him with a little kiss and a kitten lick. 

She doesn’t last long, once he starts touching her. She presses her thighs together, her tits together. It’s a soft orgasm, it washes over her in warm waves and leaves her feelings sparks down to her fingertips. She feels Seteth cum on her chest, and she’s certain he’s trying his best not to make a mess because he doesn’t cum on her neck or her face. He pulls back far enough that it’s just all in her cleavage. Goddess, she almost wants to take a picture. 

Once they’ve both had a moment to breathe, Seteth swipes some of Byleth’s hair out of her face. “Are you alright?”

Byleth nods. “Are you?”

Seteth smiles, a truly dopey grin, and leans down to kiss her. Soft, tender, but he makes sure not to press their chests together. “I could use some water. Would you like a glass?”

She nods again, and he gets up off her, after a moment. She doesn’t move from her spot, just listens to him in the kitchen. They still need to clean up from when they made dinner, she thinks to herself. She’s so tired, though. She doesn’t know that she could get up. 

Seteth comes back with two glasses and a washcloth, and dutifully cleans Byleth’s chest of his spent. She sighs happily as he does, appreciating the cloth’s warmth. Once her chest is clean, she sits up and takes a glass. 

“That was fun,” she says after a few sips. “We should do it again sometime.”

Seteth chuckles and drinks his water. “Let’s get to bed, first. You look as though you may fall asleep right here.”

They take their cups with them, Seteth insisting it’s important to keep hydrated after a fun round of titty-fucking (Byleth’s words, not his). Once they’re under the covers, Byleth snuggles up to him and they wrap their arms around one another. 

“I do hope you enjoyed it,” Seteth mumbles, “I know it was a rather... selfish request.”

Byleth smiles and hums, “It was hardly selfish. I think you’ve given me enough masturbation material for the year.”

Seteth chuckles as he nuzzles his nose against her hair, but doesn’t reply. 

“What?” She says, sweetly, “not going to tell me about how masturbation is a sin in the eyes of the goddess?”

Seteth scoffs. “I think the goddess has much more important things to worry about than whether or not people masturbate.”

Byleth hums and cuddles into his side, resting her head against his shoulder. “I think you’re probably right.” Seteth runs his hand up and down her side, just grazing her skin with his fingertips. She wraps her arms around him, pulling him closer into her grasp. He places a kiss on her forehead, and soon they both fall asleep. 

**Author's Note:**

> seteth has dry skin thats why he has all that moisturizer  
\--  
EDIT 9/25/19: Changed Seteth's wife's/Flayn's mom's name from Assal (as in the spear of Assal get it ahaha) to Morrigan bc #aesthetic


End file.
